1. Field of the Invention
The present invention relates to a processing information acquisition system in a processing machine which supplies a processing point with energy or material.
2. Description of the Related Art
In a laser cutting machine, a laser welding machine, a laser heat treatment machine, a plasma cutting machine, an arc welding machine, a wirecut machine, a sealant coating machine, an automatic painting machine, and various other types of processing machines, processing is performed by firing a laser beam, generating an arc, or applying a sealant, that is, supplying a processing point with energy or material, while moving the processing point over the workpiece. Further, at the time of processing, along with this, sometimes a shield gas or welding wire is supplied.
In such a processing machine, the position of the processing point is feedback controlled by a servo control system based on position information obtained from a pulse coder, linear scale, etc. of a servo motor performing positioning.
Further, regarding the supply of the laser beam, sealant, or other energy or material, the optimal feed rate and other processing conditions change depending on the processing speed and the shape to be processed, so the command values of the processing conditions which are transmitted to the control device also have to be changed accordingly. For example, in firing a laser beam, feeding welding wire, and applying a sealant, the amount of power of the laser excitation power supply, the feed rate at the wire reel part, the sealant feed valve opening degree, or other processing conditions are changed.
Regarding this, after the command values of the processing conditions are transmitted to the control device, the actual processing state at the processing point does not immediately change to the desired processing conditions. For example, in a laser processing machine, a certain time is required from when current is supplied to the laser generator to when the laser beam is fired. In this way, there is some delay in the response. Furthermore, the average laser output value of the actually fired laser beam is not proportional to the command value. Further, in another example, when feeding a gas or liquid to a processing point, the command value relating to the valve opening degree and the amount which is actually fed to the processing point are also not strictly proportional.
In these various types of processing machines, outputting processing information relating to the actual processing state at a processing point, including position information of the processing point, in real time simultaneously to a liquid crystal panel or other display device or to a hard disk drive or other storage device would be extremely effective in monitoring, development, troubleshooting, etc. However, for generation of laser beams or arcs and feed of sealant, instead of feedback control, open loop control is sometimes used. Therefore, acquiring processing information and outputting that processing information in real time is difficult.
Japanese Patent Publication (A) No. 2001-75622 (JP2001-75622A) discloses a servo system which is provided with a servo control device including a drive unit which drives a controlled object and with a plurality of servo compensation units and which is provided with a display device which displays control conditions of a controlled object. The servo system of 2001-75622A enables simultaneous confirmation of the effect of servo compensation processing and the legitimacy of an operation and enables quick and easy determination of the servo compensation parameters of the positioning control. Further, Japanese Patent Publication (A) No. 7-204942 (JP7-204942A) discloses a monitoring system of an electrodischarge machine which can monitor the state of change of a monitored value showing the processing state of the electrodischarge machine. Further, Japanese Patent Publication (A) No. 7-5908 (7-5908A) discloses a measuring and monitoring system which acquires signals to be measured from the system being measured, samples them at fixed time intervals, and measures and monitors them by arithmetic processing and thereby measures and monitors the position, speed, and other analog and digital signals of machine operation. Further, Japanese Patent Publication (A) No. 7-294558 (JP7-294558A) discloses a method of correction of data timing of a waveform recording and display system which automatically corrects time deviations due to differences in signal transmission paths of analog input waveforms and logic input waveforms in accordance with the sampling speed.
However, the devices described in JP2001-75622A, JP7-204942A, JP7-5908A, and JP7-294558A are ones which output a measured value to a display device or storage device. They are not ones which can estimate processing information relating to the actual processing state at a processing point and output it in real time to a display device or storage device. To output processing information relating to the actual processing state at a processing point in real time, some sort of estimation has to be performed to calculate the values.